I go with a 3 part wash.
1st) 5gal ro water 2 TBLSP B.Soda and 3 TBLSP Lemon Juice
2nd) 5 gal RO 2 TBLSP- 1 QUART 3%H202. I say this because you can also use this method to wash P. Mildew off buds but want a much stronger solution. TBH if it had mildew on it Id throw it away before even attempting to wash it. The H202 will kill or at least damage any spores of molds or mildews that for sure landed on your buds during the grow. Unless you have a heppa filter cleaning your air before it enters your tent, there is mold spores attached to it…lotsa other dust, fly wings etc also.
3rd) 5 gal straight RO or distilled water for rinse. Drip dry then into the tent 7-14 days! I took pics of my last wash buckets after 4 plant harvest if you wanna see link below.